Method of making a combination speaker grill and automotive trim panel

ABSTRACT

A method of manufacturing a rear shelf trim and speaker grill panel ( 12 ) for an automotive vehicle ( 10 ) includes steps of punching a substrate layer ( 16 ) of a polypropylene and flax material with a punch set ( 46 ) to form a grill section ( 60 ) and placing a decorative carpet layer ( 18 ) over the substrate layer ( 16 ) and molding the two layers into a combined speaker grill and rear shelf trim panel ( 12 ).

This application is a continuation-in-part of patent application U.S.Ser. No. 09/260,799 filed Mar. 1, 1999, now pending.

FIELD OF THE INVENTION

The invention relates to a method of making a rear shelf trim panel withspeaker apertures to accommodate a speaker mounted under the rear shelftrim panel.

BACKGROUND OF THE INVENTION

Many motor vehicles now have FM stereo radios or more elaborate soundsystems such as tape players, compact disc players, digital tapes andcomputer sound systems with accompanying speakers for the enjoyment ofthe driver and passengers. Furthermore, the electronics of the soundsystem have also greatly improved. As a result, of all theseimprovements, the sound emanating from a car stereo speaker has aquality that was unheard of only a few years ago.

Many after-market speakers are free standing with their own cases andspeaker grills. The speaker grill is commonly used to conceal andprotect the actual speaker cone against puncture or other damage.Factory mounted speakers are often mounted in concealed places such asbehind door panels and under rear trim shelf panels. When the speakersare positioned behind or under such panels, the panels must incorporatea speaker grill that has apertures and cutouts to reduce mufflingeffects of the panels and to promote the efficiency of sound emanatingfrom the concealed speakers into the interior of the motor vehicle.

Many known speaker grills are molded. Pins are used in the mold to formapertures through the cover to allow sound emanation. A porous cloth ornon-woven fabric may provide a fabric covering for the speaker grill.While the panel needs holes to allow transmission of sound, a lightporous cloth or fabric may cover the holes in the panel structurewithout an overly undesirable amount of sound blockage.

What is needed is an expeditious method of forming an integrated speakergrill with an automotive interior panel that has apertures incorporatedtherein to provide for the transmission of sound from the speaker intothe automotive vehicle interior.

SUMMARY OF THE DISCLOSURE

In accordance with one aspect of the invention, a process for forming acombined speaker grill and automotive interior trim panel includes theinitial step of providing a substrate layer of a heated mat materialhaving a content.of thermoplastic material such that it is moldableunder heated conditions. Preferably the mat also has a content of flaxfiber. The process also includes punching a plurality of apertures in aspeaker grill section of the heated substrate. The punching of theapertures is, in one embodiment; simultaneous with the molding step suchthat the apertures are formed through both the substrate and thedecorative layer as the substrate and decorative layer are shaped intothe final panel contour.

A decorative layer is provided onto the heated substrate. The decorativelayer is preferably a porous carpet with a thermal plastic back surface.

The substrate and the decorative layer are molded into the desiredshaped panel such as a rear shelf trim panel such that said aperturesform an integrated speaker grill section within the panel.

Preferably, a first and second mold dies form the apertures in thesubstrate. The first mold die has apertures therein and the second molddie has a punch set that fits in the apertures of the first mold die topunch apertures through both the decorative layer and the substrate asthe mold dies are closed to shape the substrate and the decorativelayers into the panel.

In one embodiment, the apertures in the substrate are formed in thespeaker grill section before the substrate is molded into its finalshape. The grill section is positioned such that pins are then receivedin the apertures in the grill section and the decorative layer ispositioned over the substrate, grill section and the pins in the mold.The mold is closed and the substrate layer, grill section and decorativelayer are molded into a shape of an automotive interior panel underpressure.

In one embodiment, the speaker grill section is a separate previouslyformed perforated member that is placed over an opening of the substratelayer such that a peripheral edge of the perforated grill sectionoverlaps an edge of the substrate layer about the opening. A hot meltadhesive is applied to the perforated grill section for adhesion to thedecorative layer.

The substrate is then removed from the pins and mold. The apertures inthe grill section are positioned under the decorative layer, i.e., themolded panel has the decorative layer spanning over the apertures in thegrill section of the substrate.

Preferably, the pins extend through a first mold die and are level withan interior surface of the first mold die. The apertures in thesubstrate are formed by a first punch set aligned with the pins to pushthrough the substrate and recess the pins. The punch set is then raisedto remove the punched scraps of substrate. The pins are then raised tointrude into the apertures in the substrate. A second mold die thatcomplements the first mold die is provided and the panel is molded intoshape with the pins extending through the first mold die and remainingin the apertures in the substrate.

In accordance with another aspect of the invention, a process forforming a combined speaker grill and automotive interior trim panel ischaracterized by the steps of providing a decorative layer that iscapable of being bonded to the substrate layer; placing the heatedsubstrate layer and decorative layer into an open mold; closing the moldand molding the substrate layer and the decorative layer into a formedautomotive interior panel under pressure between two closed mold dieswith a first mold die section having a section with a plurality of holestherein and a complementary mold die section having a plurality ofpunches that mate with the plurality of holes to punch a plurality ofapertures in the formed panel to form an integral speaker grill with thepanel; and opening the mold dies and cooling the panel to beresolidified with the substrate and decorative layers being bondedtogether and removing the molded formed panel and speaker grill from themold.

In accordance with another aspect of the invention, a process forforming a combined speaker grill and automotive interior trim panel ischaracterized by the steps of: providing a grill section and substratelayer of a heated mat material having a content of thermoplasticmaterial such that it is moldable under heated conditions; punching outa plurality of apertures in the grill section; positioning said grillsection such that a pin is received in each respective aperture with anend of the pin substantially coplanar with one side of the grillsection; providing a decorative layer that is capable of being bonded tothe substrate layer and said grill section; molding the substrate layer,grill section, and the decorative layer into a formed automotiveinterior panel under pressure between two closed mold dies with thedecorative layer spanning over the pins in the apertures in thesubstrate to form an integrated speaker grill with the panel; removingthe molded formed panel and speaker grill after the thermoplasticmaterial in the panel is cooled to allow the panel to be resolidifiedand the substrate and decorative layers to be bonded together.

In accordance with another aspect of the invention, a process forforming a combined speaker grill and automotive interior trim panel ischaracterized by the steps of: providing a substrate layer of a heatedmat material having a content of thermoplastic material such that it ismoldable under heated conditions; providing an aperture in the substratelayers; that is slightly smaller than the grill section placing aperforated grill section over the opening in the substrate with therespective edges overlapping, positioning a pin in each respective holein the grill section with an end of the pin substantially coplanar withone side of the grill section; providing a decorative layer that iscapable of being bonded to the substrate layer and grill section;molding the substrate layer grill section and the decorative layer intoa formed automotive interior panel under pressure between two closedmold dies with the decorative layer spanning over the pins in theapertures in the substrate to form a integral speaker grill with thepanel leaving an edge of the substrate layer uncovered; and punching outan additional grill section with a plurality of holes; removing themolded formed panel and speaker grill after the thermoplastic materialin the panel is cooled to allow the panel to be resolidified and thesubstrate and decorative layers to be bonded together; and removing thepunched out additional grill section for placement in an aperture of ananother substrate layer.

In accordance with another aspect of the invention, a molded interiorautomotive panel and speaker grill combination includes a moldedsubstrate layer having thermal plastic content and a flax fiber content.A plurality of apertures through the substrate are aligned with aspeaker-mounted therebehind. A decorative layer is bonded on top of thesubstrate material and molded thereto. In one embodiment, the decorativelayer is a porous carpet layer that spans over the plurality ofapertures. In another embodiment, the decorative layer also hasapertures therethrough that align with the apertures in the substrate.In another embodiment, a separate grill section is received over anopening through the substrate. Both the grill section and substrate aremade from the same material. The grill is then bonded to the substrateabout the aperture with the carpet layer spanning over both the grilland substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference is now made to the accompanying drawings in which:

FIG. 1 is a perspective view of a rear shelf trim panel according to oneembodiment of the invention;

FIG. 2 is an enlarged segmented view of rear shelf trim panel shown inFIG. 1 with a speaker mounted thereunder;

FIG. 3 is a fragmentary sectional view through the lower and upper moldsbefore molding of the rear trim panel shown in FIG. 2;

FIG. 4 is a view similar to FIG. 3 during a cutting and molding step;

FIG. 5 is a view similar to FIG. 4 after the upper mold is raisedsubsequent to the cutting and molding step;

FIG. 6 is a fragmentary, segmented and schematic view of a lower moldand punch press illustrating a method of manufacturing a modifiedembodiment according to the invention;

FIG. 7 is a view similar to FIG. 6 with the punch press punchingapertures through the substrate layer;

FIG. 8 is a view similar to FIG. 7 showing the punch press lifted upafter punching apertures in the substrate layer;

FIG. 9 illustrates the placing of a decorative layer and an upper molddie over the substrate layer and lower mold die;

FIG. 10 is a view similar to FIG. 9 with the lower and upper mold diesshown in the closed position;

FIG. 11 is a view similar to FIG. 10 with the mold dies opened and theformed rear shelf trim panel lifted off the lower mold die;

FIG. 12 is a perspective and exploded view of an alternate embodimentwith the upper and lower mold pieces before assembly and molding;

FIG. 13 is a cross-sectional view of taken along the lines 13—13 shownin FIG. 12 with the upper and lower molds being closed;

FIG. 14 is a view similar to FIG. 12 after molding and opening of themolds; and

FIG. 15 is a cross-sectional view taken along lines 15—15 shown in FIG.14

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown in FIG. 1, an automotive vehicle 10 has a rear shelf trim panel12 mounted in the interior 11 of the vehicle and has speakers 14concealably mounted thereunder. The rear shelf trim panel 12 as moreclearly shown in FIG. 2 has a substrate layer 16 and a decorative carpetlayer 18. A plurality of apertures 20 and 22 extend through thesubstrate layer 16 and carpet layer 18 respectively. The apertures 20through the substrate layer 16 are aligned with the apertures 22 throughthe carpet layer 18 to form passages that allow sound to transmit fromthe speaker 14 and into the automotive interior 11.

The particular shape and contour of the rear shelf trim panel may varydepending on the model vehicle. It may also accommodate a rear brakelight that is not shown for simplicity of the drawing.

The rear shelf trim panel has its substrate layer 16 made from a blendof flax and polypropylene unwoven mat. While the composition andingredients of the mat may change it is desirable to have a blend of 50%polypropylene and 50% flax by weight. It is easily foreseen that thepercentage of flax may vary between 40-70% be weight depending on theparticular requirements and applications. The unwoven mat may have anuncompressed thickness of 11 mm. The mat may then be heated andcompressed to 3 mm substrate layer 16 in order to provide the desiredstructural rigidity for most applications in a rear shelf trim panelenvironment. The mat may be heated to 200° C. to provide that thethermal plastic, polypropylene, is in a molten and moldable state.

The preheated substrate layer 16 is positioned in a mold assembly 24that has a core side mold die 26 and a cavity or upper die 28 as shownin FIG. 3. The core side 26 has a die insert 30 and the cavity side 28has a punch insert 32. The die insert 30 has a plurality of holes 34that receive the punch dies 36 of insert 32. A decorative layer such asa porous carpet layer 18 with a polypropylene back surface is placedover the substrate layer 16.

The mold dies 26 and 28 are at ambient temperature and are heated onlyby the heated substrate layer 16 transfers to the mold dies. A coolingmechanism (not shown) may be provided to dissipate excess heat from themold assembly 24.

The mold dies 26 and 28 are closed as shown in FIG. 4 such that thepunch dies 34 push into the holes 34 in die insert 32. This causespunched scraps 38 of the carpet layer 18 and substrate layer 16 to bepunched out and drop through the holes 34 in the die insert 30 to formapertures 20 and 22 simultaneously with the molding of the panel 12. Apressure of five bars provides sufficient compressive force to achievepart configuration within the mold.

As shown in FIG. 5, after the rear shelf trim panel 12 is molded, themold dies are opened and the panel 12 is removed. The scraps 38 are alsoremoved by a mechanism (not shown) that strokes once per cycle to removethe scraps 38.

Another embodiment can be made where the carpet layer 18 does not haveapertures 22 therethrough. Alternatively, the carpet layer 18 spans overthe apertures 20 in the substrate layer 16. The process for making thisembodiment is schematically illustrated in FIGS. 6-11. In this process,a set of retractable pins 40 are biased upward by a platform 42 set onsprings 44. The pins 40 extend through the apertures 34 in the dieinsert 30. The substrate layer 16 is placed in the core side mold die 26over the retractable pins as shown in FIG. 6. As shown in FIG. 7, a dieset punch section 46 has punch pins 48 that are aligned with pins 40 andpunched to be received in holes 40. As a result the pins 48 punch holes20 through substrate layer 16. As shown in FIG. 8, the punch set islifted up and removed. The punched scraps 54 can be removed by liftingthe pins 40 such they extend now through formed apertures 20 in layer16. Alternatively, the pins 48 of the punch set may have barbed lowerends which pull out the scrap pieces 54 and be removed from the pins 48by a comb style sweeper. A further modification may be that pins 48 haveoptional stripper sleeves to remove the attached scrap members 54. Theimportant aspect is that the scraps 54 are removed so as not tointerfere with the subsequent described steps.

As shown in FIG. 9, a decorative layer 18 such as the previouslydescribed carpet layer with a polypropylene back surface can then beplaced over the substrate layer 16 and apertures 20. Pins 40 areretained in a lifted position and remain in the apertures 20. As shownin FIG. 10, an upper mold die 56 is then closed upon the lower mold die26 and molds the carpet layer 18 and substrate layer 16 into shape andbonds the two together. After sufficient cooling, the upper mold die 56is then lifted and the mold is open. The pins 40 are retracted from theapertures 20 and the formed panel 12 is then removed from core side molddie 26.

In this fashion, the apertures 20 are concealed by the porous carpetlayer 18 but function substantially the same as the apertures 20 in thefirst embodiment, namely by allowing excellent transmission of sound ofall audible frequencies from a speaker 14 that is mounted under thesubstrate layer 12 and into an interior 11 of an automotive vehicle 10.

In the alternate embodiment disclosed in FIGS. 12-15, each perforatedgrill section 60 is a separate member that is laid over as opening 62 insubstrate layer 16. The opening 62 is through a recessed peripheral edge64 that is recessed a single thickness of the grill section 60.

The grill section 60 contains the plurality of aperture 20 and is placedover aligned stationary pins 140 in lower mold are 126 after substratelayer 116 is positioned thereon with the mold having recess section 164to accommodate recessed peripheral edge 64. A hot melt or other adhesiveis then applied to the top surface 66 of the grill section 60.

A carpet layer 118 is placed over substrate 116 to cover over both grillsections 60 but leaving end section 168 exposed. The mold dies 128 and126 are closed where grill sections 60 and carpet larger 118 are moldedand bonded to the substrate layer 116 over openings 62 as shown in FIG.15.

Simultaneously as shown in FIG. 13, two additional grill sections 60 tobe used in the future are formed with aperture 20 via the punch and dieset 130 and 136. Two end sections 168 of the substrate 16 are positionedover a die insert 130 in die 126. The die insert 130 has a plurality ofapertures 134 that receive punch die 136 in the upper mold die 128.Scraps 138 drop through aperture 134. The molds 126 and 128 have cuttersto also cut the grill section 60 from the end section 168 of thesubstrate. The mold dies opened after sufficient cooling and the partsare demolded forming a complete panel 112; two additional grill sections60 and two scrap ends 168.

The cycle is then repeated with the additional grill sections 60 beingused to form another panel 112.

Other variations and modifications are possible without departing fromthe scope and spirit of the present invention as defined by the appendedclaims.

I claim:
 1. A process for forming an automotive interior trim panel,having apertures formed in a substrate layer, characterized by the stepsof: providing a substrate layer comprising thermoplastic material over afirst mold die; punching a plurality of apertures in said substratelayer using at least one punch set; raising said at least one punch set;raising one or more sets of pins aligned with said at least one punchset through said first mold die into said apertures in said substrateafter said apertures are formed; providing a decorative layer onto saidsubstrate; providing a second mold die that complements said first molddie and closing said first and second mold dies; molding said panel intoshape with said pins extending through said first mold die and remainingin said apertures in said substrate during said molding of said panel;removing said substrate from said pins such that said molded panel hassaid decorative layer spanning over said apertures in said substrate. 2.The process of claim 1 wherein the substrate layer is a mat materialhaving a content of thermoplastic material such that it is moldableunder heated conditions.
 3. The process of claim 1 wherein the substratelayer is heated prior to punching and molding.
 4. The process of claim 1wherein the apertures in the substrate layer form a grill section. 5.The process of claim 1 wherein the decorative layer is a porous carpetlayer.
 6. The process of claim 1 wherein the one or more sets of pinsare spring-biased.
 7. The process of claim 1 wherein said punch set andsaid one or more sets of pins are positioned such that the punch set, ina fully extended position, contacts said one or more sets of pins anddepresses said one or more sets of pins beneath a surface of the firstmold die.
 8. The process of claim 1 wherein the at least one punch setare movably mounted in and extend through at least a portion of thesecond mold die.
 9. The process of claim 1 wherein the one or more setsof pins are movably mounted in and extend through at least a portion ofthe first mold die.